/* 数据结构 栈的实现 Stack.h
 * author : star
 */
 
//防止重复定义
#ifndef STACK_H
#define STACK_H

#include "defs.h"

//初始化大小为n的栈 
int InitSqstack(SQSTACK *S, int n)
{
	S->data = (ElemType *)malloc(n * sizeof(ElemType));
	if(S->data == NULL)
		return 0;
	S->size = n;
	S->top  = -1;
	return 1;
}

//销毁栈
void DestroySqstack(SQSTACK *S)
{
	free(S->data);
	S->data = NULL;
	S->top  = -1;
	S->size = 0;
}

//判断栈空、栈满
int IsSqstackEmpty(SQSTACK S)
{
	return S.top == -1;
}

int IsSqstackFull(SQSTACK S)
{
	return S.top == S.size-1;
}

//入栈
int PushS(SQSTACK *S, ElemType e)
{
	if(IsSqstackFull(*S))
		return 0;
	++S->top;
	S->data[S->top] = e;
	return 1;
}

//出栈
int PopS(SQSTACK *S, ElemType *e)
{
	if(IsSqstackEmpty(*S))
		return 0;
	*e = S->data[S->top];
	--S->top;
	return 1;
}

//初始化链式栈
int InitLinkstack(LINKSTACK *S)
{
	*S = (LINKSTACK)malloc(sizeof(LSNODE));
	if(*S == NULL)
		return 0;
	(*S)->next = NULL;
	return 1;
}

//销毁链式栈
int DestroyLinkstack(LINKSTACK *S)
{
	LSNODEPTR q, p;
	p = *S;
	while(p)
	{
		q = p;
		p = p->next;
		free(q);
	}
	*S = NULL;
}

//判断链栈空、满
IsLinkstackEmpty(LINKSTACK S)
{
	return S->next == NULL;
}

IsLinkstackFull(LINKSTACK S)
{
	return S->next != NULL;
}

//入链栈 
int PushL(LINKSTACK S, ElemType e)
{
	LSNODEPTR p;
	p = (LSNODEPTR)malloc(sizeof(LSNODE));
	if(p == NULL)
		return 0;
	p->data = e;
	p->next = S->next;
	S->next = p;
	return 1;
}

//出链栈
int PopL(LINKSTACK S, ElemType *e)
{
	LSNODEPTR p;
	p = S->next;
	if(p == NULL)
		return 0;
	S->next = p->next;
	*e = p->data;
	free(p);
	return 1;
}

#endif